The present invention relates to a silicon steel core spacing structure for improving induction, more particularly to a silicon steel core that provides an appropriate induction to a transformer or a choke coil and improves the saturation of the magnetic core.
At present, various transformers or choke coils are generally used in the electric appliances of different functions. The transformer or choke coil also plays an important role in the power supply of an electric appliance. The transformer or choke coil can improve the percentage of use of a power supply and lower unnecessary power supply interference of the power system. Besides enhancing the life of electric appliances, the transformer or choke coil also has effect on environmental protection. Therefore, the transformer or choke coil becomes one of the indispensable simple-to-use components of electric appliances.
The silicon steel core of general transformers or choke coils comprises a first silicon steel core and a second silicon steel core either in xe2x80x9cE-shapexe2x80x9d or in xe2x80x9cI-shapexe2x80x9d; when the first and second silicon steel cores are connected, the magnetic flux section defines a corresponding connecting mode, and has an insulated space between the corresponding central magnetic flux section. The thickness of such spacer can adjust the gap of the magnetic flux section at both wings of the first and second silicon steel cores. Since the size of the gap and the property of the central spacer determine the magnitude of the inductance outputted from the transformer or choke coil. If the gap is small or has poor spacing property, the inductance so produced is large, and the choke coil at light load can still maintain a sufficient inductance. However the load of high wattage will cause saturation to the magnetic core easily. If the gap is large or has good spacing property, the inductance so produced is small. Although the heavy load will not be saturated easily, the light load will not be able to attain the necessary inductance, unless more copper coils or silicon steel spacers are added to increase the inductance.
The material used for the spacer between the first and second silicon steel cores of the aforementioned transformer or choke coil is paper or plastic, mainly because paper or plastic has an easily adjustable thickness. Therefore the spacer disposed at the central magnetic flux sections can be used to adjust the gap between the two wings and the central spacing property. However, magnetic force can penetrate paper or plastic material easily, and thus gives a poor result and even makes the spacer at the central magnetic flux section existing in name only. Therefore, only the gap between the magnetic flux sections of the two wings is used to adjust inductance.
Further, the harmonic test for the safety regulations of the European specification generally demands an upper limit (depending on the set required power of the electric appliance) and a lower limit (at most 75 W for the present specification, but will be 50 W by 2004). Since the transformer or choke coil manufactured with foregoing silicon steel core spacer needs to meet the requirement of the lower limit, the inductance must be increased and the corresponding gap between the silicon steel cores must be decreased. Therefore, when the electric appliance or equipment is at heavy load, the magnetic core of the transformer or choke coil will be saturated easily, and such equipment at heavy load is unable to pass the harmonic test according to the safety regulations. To pass the test of safety regulations, manufacturers have to increase the number of copper coils or silicon steel cores in order to improve the inductance, and thus increasing the level of difficulty and the cost of the production.
The primary objective of the present invention is to solve the aforementioned problems and eliminate the drawbacks of cited prior arts by providing a silicon steel core structure that can easily adjust the inductance. To achieve the foregoing objective, this invention comprises a shielded copper spacer at the magnetic flux section between two silicon steel cores, and the magnetic reluctance of such copper spacer is relatively low that can guide the traveling path of the magnetic line of force, and thus lower the magnetic flux density passing through the copper spacer. Therefore, the power and induction outputted by a transformer or a choke coil can comply with the tests of safety regulations.